In, for example, certain water feed and water washing operations it is necessary to utilize a quick opening and quick closing valve to control the water supply so that acurate control of the water input may be obtained, and so that water flow will not occur at reduced rates as the valve is opened and closed. For example, in concrete mixing operations, a certain amount of water must be introduced to the concrete mixture, and adequate control of the water cannot be obtained unless the valve is of the quick acting type. The instant valve was developed primarily for this purpose, but may be used in other processes requiring a quick opening and quick closing valve.